Transition-transversion mutations in the polyketide synthase gene of Aspergillus section Nigri

Abstract

This study determined the transition-transversion mutation in the pks gene of Aspergillus section Nigri in order to gain insight into the patterns of nucleotide base substitution and the process of molecular evolution using standard recommended techniques. Results obtained depict frequent occurrence of transition (23 ± 0.96) than transversion (11.37 ± 1.38) (p < 0.05) with C/T being the most frequently observed transitional base substitution and C/A the most frequently occurring transversional base change. The number of single base insertions (56 ± 1.00) were significantly higher than the observed single base deletions (38 ± 2.00) (p < 0.05) while varying degrees of two or more base deletions and insertions were also observed both inside and outside the open reading frame. The maximum likelihood value estimated for the pks gene was calculated to be -9458.80 in 423 positions of the final dataset while the transition-transversion ratio was estimated to be 0.50. The Tajima's neutrality test approaches seven (7) with the nucleotide diversity estimated to be approximately 65%. Evolutionary test depicts positive selection as ratio of non synonymous to synonymous divergence was found to be greater than ratio of the number of non synonymous to synonymous polymorphisms. The proportion of substitution driven by positive selection was calculated to be approximately 96.2%. This research therefore provides an insight into the understanding of pks gene mutation patterns as some of the observed indels resulted in frame shift mutations.

Biological Resolution of Virulence Genes of Salmonella Species from different Microbiomes

“…However, this observation may be attributable to differences in samples used for the experiment and geographical location. Also, of particular importance to note is the possibility of some of the highlighted genes to mutate through several mechanisms and therefore leading to evolution of more pathogenic strains in future (Thomas et al, 2019). Our study, therefore documents a non microbiome specific distribution of Salmonella spp and further shows that most of the food, human and environmentally distributed Salmonella spp could cause outbreak as a result of the presence of different virulence genes that are potent genetic markers of pathogenicity.…”

Identification, evolution, and expression of GDSL-type Esterase/Lipase (GELP) gene family in three cotton species: a bioinformatic analysis

“…Gene base substitutions, including base transitions and base transversions that result in silence, missense, nonsense, and termination codon mutation, are major driving forces during gene evolution, leading to structural variation and functional alteration or loss of genes [ 36 , 38 , 98 , 99 ]. In order to explore the evolutionary trend of the cotton GELP family genes at the time dimension, the base substitution saturation between orthologous or paralogous gene pairs that evolved from ancestral diploid to descendant tetraploid was determined by calculation (Fig.…”

Metagenomic tracking of microbial consortia of cassava flakes (garri)

“…Consequently, the representative sequence counts and the average GC contents observed in this study further reinforced that the analyzed samples were significantly rich in microbial contaminants. This is contingent upon the fact that the genomic DNA base composition is significantly associated with genome size and holocentric chromosomal structure (Smarda et al, 2014;Thomas et al, 2019). According to Smarda et al (2014), these genomic DNA base compositions are also known to significantly affect genome functioning and species ecology.…”